#include #include using namespace std; using namespace atcoder; typedef int64_t lint; #define rep(i, n) for(int i=0; i; using vvi = vector>; template inline void vin(vector& v) { rep(i, v.size()) cin >> v.at(i); } template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } template inline void drop(T x) { cout << x << endl; exit(0); } template void vout(vector v) { rep(i, v.size()) { cout << v.at(i) << ' '; } cout << endl; } constexpr lint LINF = LLONG_MAX/2; using mint = modint998244353; using vm = vector; int main() { lint N, X, Y; cin >> N >> X >> Y; lint a=0, b=0, c=0, x, y, z; if (X > Y) swap(X, Y); if (Y-X == 1) drop(0); a = Y-X-1; if (X == 1) a++; if (Y == N) a++; vm dp(a); dp[0] = 1; rep(i, a-1) { dp[i+1] += dp[i]; if (i-2 >= 0) dp[i+1] += dp[i-2]; } std::cout << dp[a-1].val() << '\n'; }